TW201407223A - Image lens assembly, image capturing device and mobile terminal - Google Patents

Abstract

An image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, wherein at least one surface of the second lens element is aspheric. The third lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein at least one surface of the second lens element is aspheric. The fourth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein both surfaces of the fourth lens element are aspheric, and the image-side surface thereof has at least one inflection point. When a specific condition is satisfied, the sensitivity can be reduced and the compact size thereof can be maintained.

Description

Imaging lens group, image capturing device, and portable device

The present invention relates to an imaging lens set, and more particularly to a miniaturized imaging lens set for use in an electronic product.

In recent years, with the rise of portable electronic products with photographic functions, the demand for optical systems has increased. Generally, the photosensitive element of the optical system is nothing more than a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor Sensor (CMOS Sensor), and with the advancement of semiconductor process technology, As the size of the pixel of the photosensitive element is reduced, the optical system is gradually developed in the field of high-pixels, and thus the requirements for image quality are increasing.

The optical system traditionally used in portable electronic products mostly uses a three-piece lens structure, but the popularity of high-profile portable mobile devices such as smart phones and tablet PCs drives opticals. The system's rapid rise in pixel and imaging quality, the conventional optical system will not be able to meet higher-order photography systems.

Although there are developments in the traditional four-piece optical system, the second The thickness of the lens and the third lens are not evenly arranged, and the sensitivity of the optical system cannot be lowered, and the miniaturization of the optical system cannot be effectively maintained, resulting in poor imaging performance and disadvantageous for mounting on a miniaturized electronic product.

The present invention provides an imaging lens group in which the thickness distribution of the second lens and the third lens is averaged, which is advantageous in reducing the sensitivity while maintaining the miniaturization thereof.

According to the present invention, there is provided an imaging lens group including a first lens, a second lens, a third lens, and a fourth lens in order from the object side to the image side. The first lens has a positive refractive power, and the object side surface is convex at the near optical axis. The second lens has a negative refractive power, and the object side surface is concave at the near optical axis, and the image side surface is concave at the near optical axis, and has at least one surface aspherical. The third lens has a positive refractive power, and the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis, and has at least one surface aspherical. The fourth lens has a negative refractive power, and the image side surface has a concave surface at the near optical axis, and both the object side surface and the image side surface are aspherical surfaces, wherein the fourth lens image side surface has at least one inflection point. In the imaging lens group, the refractive power lens has four pieces and each lens has a pitch on the optical axis. The thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, second. The radius of curvature of the side surface of the lens object is R3, the radius of curvature of the side surface of the second lens image is R4, the focal length of the second lens is f2, and the focal length of the fourth lens is f4, which satisfies the following condition: 0.50<CT3/CT2<1.12 ; -0.85 < (R3 + R4) / (R3-R4) < .0.90; and 0 < f4 / f2 < 0.90.

According to the present invention, there is further provided an image taking device comprising the imaging lens group as described in the above paragraph and an electronic photosensitive element, wherein the electronic photosensitive element is coupled to the imaging lens group.

According to the present invention, there is further provided a portable device comprising the image taking device of the above paragraph.

According to the present invention, there is further provided an imaging lens group comprising, in order from the object side to the image side, a first lens, a second lens, a third lens and a fourth lens. The first lens has a positive refractive power, and the object side surface is convex at the near optical axis. The second lens has a negative refractive power and is made of a plastic material, and the object side surface is concave at a near optical axis, and at least one surface thereof is aspherical. The third lens has a positive refractive power and is made of a plastic material, and the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis, and at least one surface thereof is aspherical. The fourth lens has a negative refractive power and is made of a plastic material, and the image side surface is concave at the near optical axis, and the object side surface and the image side surface are all aspherical surfaces, wherein the fourth lens image side surface has at least one inflection point . The imaging lens group has four refractive power lenses and each of the lenses has a spacing on the optical axis. The imaging lens group further includes an aperture disposed between the object and the first lens, and the second lens is disposed on the optical axis. The thickness is CT2, the thickness of the third lens on the optical axis is CT3, the radius of curvature of the second lens object side surface is R3, the radius of curvature of the second lens image side surface is R4, and the focal length of the second lens is f2, fourth The focal length of the lens is f4, the radius of curvature of the fourth lens object side surface is R7, and the radius of curvature of the fourth lens image side surface is R8, which satisfies the following conditions: 0.50<CT3/CT2<1.12; -1.50<(R3+R4)/(R3-R4)<0.90; 0<f4/f2<0.90; and 0<(R7+R8)/(R7-R8)<3.5.

According to the present invention, there is further provided an image taking device comprising the imaging lens group of the above paragraph and an electronic photosensitive element, wherein the electronic photosensitive element is coupled to the imaging lens group.

According to the present invention, there is further provided a portable device comprising the image taking device of the above paragraph.

When CT3/CT2 satisfies the above conditions, the thickness of the second lens and the third lens are evenly arranged, which is advantageous in reducing the sensitivity of the imaging lens group while maintaining the miniaturization thereof.

When (R3+R4)/(R3-R4) satisfies the above conditions, it is advantageous to correct the aberration of the imaging lens group.

When f4/f2 satisfies the above conditions, it contributes to the correction of the aberration of the imaging lens group, and the miniaturization thereof can be promoted.

When (R7+R8)/(R7-R8) satisfies the above conditions, it is advantageous to enhance the correction of aberrations and contribute to maintaining miniaturization.

10, 20, 30‧‧‧ portable devices

11, 21, 31‧‧‧ image capture device

100, 200, 300, 400, 500, 600, 700, 800, 900‧ ‧ aperture

110, 210, 310, 410, 510, 610, 710, 810, 910‧‧‧ first lens

111, 211, 311, 411, 511, 611, 711, 811, 911 ‧ ‧ ‧ side surface

112, 212, 312, 412, 512, 612, 712, 812, 912‧‧‧ image side surface

120, 220, 320, 420, 520, 620, 720, 820, 920‧‧‧ second lens

121, 221, 321, 421, 521, 621, 721, 821, 921 ‧ ‧ ‧ side surface

122, 222, 322, 422, 522, 622, 722, 822, 922‧‧‧ image side surface

130, 230, 330, 430, 530, 630, 730, 830, 930‧‧‧ third lens

131, 231, 331, 431, 531, 631, 731, 831, 931 ‧ ‧ ‧ side surface

132, 232, 332, 432, 532, 632, 732, 832, 932 ‧ ‧ side surface

140, 240, 340, 440, 540, 640, 740, 840, 940 ‧ ‧ fourth lens

141, 241, 341, 441, 541, 641, 741, 841, 941 ‧ ‧ ‧ side surface

142, 242, 342, 442, 542, 642, 742, 842, 942 ‧ ‧ side surface

150, 250, 350, 450, 550, 650, 750, 850, 950 ‧ ‧ infrared filter

170, 270, 370, 470, 570, 670, 770, 870, 970 ‧ ‧ imaging surfaces ‧ ‧ ‧ 160, 260, 360, 460, 560, 660, 760, 860, 960 electronic photosensitive elements

f‧‧‧The focal length of the imaging lens group

Aperture value of Fno‧‧‧ imaging lens set

Half of the maximum angle of view in the HFOV‧‧ imaging lens group

N2‧‧‧ refractive index of the second lens

CT2‧‧‧ thickness of the second lens on the optical axis

CT3‧‧‧ thickness of the third lens on the optical axis

T12‧‧‧The distance between the first lens and the second lens on the optical axis

T23‧‧‧Separation distance between the second lens and the third lens on the optical axis

Sag2l‧‧‧ horizontal displacement distance of the second lens object side surface on the optical axis to the second lens object side surface maximum effective radius position on the optical axis

Sag22‧‧‧The horizontal displacement distance of the optical lens from the intersection of the side surface of the second lens image on the optical axis to the maximum effective radius of the side surface of the second lens image

R1‧‧‧The radius of curvature of the side surface of the first lens object

R2‧‧‧ radius of curvature of the side surface of the first lens image

R3‧‧‧ radius of curvature of the side surface of the second lens

R4‧‧‧ radius of curvature of the side surface of the second lens image

R7‧‧‧ radius of curvature of the side surface of the fourth lens object

R8‧‧‧ radius of curvature of the side surface of the fourth lens

F2‧‧‧The focal length of the second lens

F4‧‧‧The focal length of the fourth lens

SD‧‧‧ aperture to the distance of the side surface of the fourth lens image on the optical axis

TD‧‧‧Distance from the first lens object side surface to the fourth lens image side surface on the optical axis

Maximum viewing angle in the FOV‧‧· imaging lens group

1 is a schematic view showing an image capturing apparatus according to a first embodiment of the present invention; and FIG. 2 is a spherical aberration, astigmatism, and distortion of the first embodiment from left to right. FIG. 3 is a schematic view showing an image capturing apparatus according to a second embodiment of the present invention; and FIG. 4 is a spherical aberration, astigmatism, and distortion curve of the second embodiment from left to right; The figure shows a schematic diagram of an image taking device according to a third embodiment of the present invention; FIG. 6 is a left-to-right sequence of spherical aberration, astigmatism and distortion curves of the third embodiment; FIG. 7 is a diagram showing A schematic diagram of an image taking device according to a fourth embodiment of the present invention; FIG. 8 is a spherical aberration, astigmatism, and distortion curve of the fourth embodiment from left to right; and FIG. 9 is a fifth embodiment of the present invention. A schematic diagram of an image capturing device; FIG. 10 is a spherical aberration, astigmatism, and distortion curve of the fifth embodiment from left to right; and FIG. 11 is a view showing an image capturing device according to a sixth embodiment of the present invention. FIG. 12 is a schematic diagram showing spherical aberration, astigmatism, and distortion curves of the sixth embodiment from left to right; and FIG. 13 is a schematic diagram of an image capturing apparatus according to a seventh embodiment of the present invention; The figure is the spherical aberration, astigmatism and distortion of the seventh embodiment from left to right. FIG. 15 is a schematic view showing an image capturing apparatus according to an eighth embodiment of the present invention; and FIG. 16 is a spherical aberration, astigmatism, and distortion curve of the eighth embodiment from left to right; The figure shows a schematic diagram of an image capturing device according to a ninth embodiment of the present invention; FIG. 18 is a spherical aberration, astigmatism and distortion curve of the ninth embodiment from left to right; 1 is a schematic diagram of parameters Sag21 and Sag22 of an imaging lens group in the image capturing device; FIG. 20 is a schematic view showing a portable device according to a tenth embodiment of the present invention; and FIG. 21 is a view showing an eleventh embodiment according to the present invention. A schematic diagram of a portable device; and FIG. 22 is a schematic diagram of a portable device in accordance with a twelfth embodiment of the present invention.

The present invention provides an imaging lens group including a first lens, a second lens, a third lens, and a fourth lens from the object side to the image side, wherein the refractive lens in the imaging lens group is four.

There is a spacing between any two of the first lens, the second lens, the third lens and the fourth lens of the imaging lens group, that is, the first through The mirror, the second lens, the third lens, and the fourth lens are four non-adhesive lenses. Since the process of the adhesive lens is more complicated than that of the non-adhesive lens, especially in the bonding surface of the two lenses, a high-precision curved surface is required in order to achieve a high degree of adhesion when the two lenses are bonded, and may also be caused by the offset during the bonding process. Poor adhesion, affecting the overall optical imaging quality. Therefore, the imaging lens assembly of the present invention is provided with a pitch between the four lenses to improve the problems caused by the adhesive lens.

The first lens has a positive refractive power, and the object side surface is convex at the near optical axis. Thereby, the positive refractive power of the first lens can be appropriately adjusted to help shorten the total length of the imaging lens group.

The second lens has a negative refractive power, and the object side surface is concave at the near optical axis, and the image side surface may be concave at the near optical axis. Thereby, the aberration of the imaging lens group can be effectively corrected.

The third lens has a positive refractive power, and the object side surface is a concave surface at the near optical axis, and the image side surface is convex at the near optical axis. Thereby, the distribution of the positive refractive power in the imaging lens group is balanced, the sensitivity is lowered, and the astigmatism can be corrected.

The fourth lens has a negative refractive power, and the image side surface is concave at the near optical axis, wherein the fourth lens image side surface has at least one inflection point. Thereby, the Principal Point of the imaging lens group can be moved away from the imaging surface, which is advantageous for shortening the back focal length to maintain miniaturization, and can effectively suppress the incident angle of the off-axis field light, so that the response of the electronic photosensitive element Increased efficiency.

The thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, which satisfies the following condition: 0.50 < CT3 / CT2 < 1.12. By the thickness of the second lens and the third lens being evenly arranged, it is advantageous to reduce the thickness Like the sensitivity of the lens group, while maintaining its miniaturization. Preferably, the following conditions are satisfied: 0.65 < CT3 / CT2 < 1.05.

The radius of curvature of the second lens object side surface is R3, and the radius of curvature of the second lens image side surface is R4, which satisfies the following condition: -1.50 < (R3 + R4) / (R3 - R4) < 0.90. Thereby, it is advantageous to correct the aberration of the imaging lens group. Preferably, the following conditions are met: -1.10 (R3+R4)/(R3-R4)<0.90. More preferably, the following conditions are satisfied: -0.85 < (R3 + R4) / (R3 - R4) < 0.90. More preferably, the following conditions are satisfied: -0.60 < (R3 + R4) / (R3 - R4) < 0.45.

The focal length of the second lens is f2, and the focal length of the fourth lens is f4, which satisfies the following condition: 0 < f4 / f2 < 0.90. Thereby, it contributes to the correction of the aberration of the imaging lens group, and the miniaturization thereof can be promoted. Preferably, the following conditions are satisfied: 0.20 < f4 / f2 < 0.75.

The imaging lens group may further include an aperture disposed between the object and the first lens. The distance from the aperture to the fourth lens image side surface on the optical axis is SD, and the distance from the first lens object side surface to the fourth lens image side surface on the optical axis is TD, which satisfies the following condition: 0.85<SD/TD< 1.15. Thereby, it contributes to enhancing the telecentric effect of the imaging lens group.

The distance between the first lens and the second lens on the optical axis is T12, and the distance between the second lens and the third lens on the optical axis is T23, which satisfies the following condition: 1.0<T23/T12<5.0. Therefore, proper adjustment of the pitch configuration helps to improve the production yield.

The maximum viewing angle in the imaging lens group is FOV, which satisfies the following conditions: 70 degrees < FOV < 110 degrees. Thereby, the imaging lens group can have a large viewing angle Features for a wide range of images.

The radius of curvature of the first lens object side surface is R1, and the radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -1.5 < (R1 + R2) / (R1 - R2) < 0. Thereby, it is advantageous to reduce the generation of spherical aberration and astigmatism.

The radius of curvature of the fourth lens object side surface is R7, and the radius of curvature of the fourth lens image side surface is R8, which satisfies the following condition: 0 < (R7 + R8) / (R7 - R8) < 3.5. Thereby, it is advantageous to enhance the correction of the aberration and help to maintain miniaturization. Preferably, the following conditions are met: 1.0 (R7+R8)/(R7-R8)<3.0.

The horizontal displacement distance of the second lens object side surface on the optical axis to the second lens object side surface at the maximum effective radius position on the optical axis is Sag21, and the second lens image side surface is on the optical axis to the second through The horizontal effective displacement distance of the mirrored side surface at the maximum effective radius position on the optical axis is Sag22, which satisfies the following condition: -1.0<|Sag22|/Sag21<0. Thereby, the angle of incidence of light can be effectively suppressed, and the image quality is improved.

The refractive index of the second lens is N2, which satisfies the following condition: 1.58 < N2 < 1.65. Thereby, it contributes to the reduction of aberrations.

In the imaging lens set provided by the present invention, the material of the lens may be plastic or glass. When the lens is made of plastic, it can effectively reduce the production cost. In addition, when the lens is made of glass, the degree of freedom in the configuration of the refractive power of the imaging lens group can be increased. In addition, the object side surface and the image side surface in the imaging lens group may be aspherical surfaces, and the aspherical surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration and thereby reduce the use of the lens. The number can therefore effectively reduce the total length of the imaging lens group of the present invention.

Furthermore, in the imaging lens assembly provided by the present invention, if the lens surface is convex and the convex surface is not defined, the lens surface is convex at the near optical axis; When the lens surface is concave and the concave position is not defined, it indicates that the lens surface is concave at the near optical axis.

In addition, in the imaging lens group of the present invention, at least one aperture can be disposed as needed to reduce stray light, which helps to improve image quality.

In the imaging lens assembly of the present invention, the aperture arrangement may be a front aperture or a center aperture, wherein the front aperture means that the aperture is disposed between the object and the first lens, and the center aperture means that the aperture is disposed on the first lens and Between the imaging surfaces. If the aperture is a front aperture, the exit pupil of the imaging lens group can be extended to a long distance from the imaging surface to have a telecentric effect, and the CCD or CMOS image of the electronic photosensitive element can be increased. Efficiency; if it is a center aperture, it helps to expand the field of view of the system, giving the imaging lens unit the advantage of a wide-angle lens.

The imaging lens group of the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied to three-dimensional (3D) image capturing, digital camera and mobile device in various aspects. In portable electronic imaging systems such as digital tablets and wearable devices.

The present invention provides an image taking device comprising the aforementioned imaging lens group and an electronic photosensitive element, wherein the electronic photosensitive element is disposed on an imaging surface of the imaging lens group. The optical sensitivity of the image capturing device can be reduced by the average setting of the thickness of the second lens and the third lens of the imaging lens group in the image capturing device, and Maintaining its miniaturization will help it be mounted on small-sized electronic devices. Preferably, the image taking device may further comprise a barrel (Barrel Member), a support device (Holder Member) or a combination thereof.

The invention provides a portable device comprising the aforementioned image capturing device. Thereby, it is possible to have advantages such as low sensitivity and miniaturization. Preferably, the portable device may further include a control unit, a display unit, a storage unit, a temporary storage unit (RAM), or a combination thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the light of the above-described embodiments, the specific embodiments are described below in detail with reference to the drawings.

<First Embodiment>

Please refer to FIG. 1 and FIG. 2 , wherein FIG. 1 is a schematic diagram of an image capturing apparatus according to a first embodiment of the present invention, and FIG. 2 is a spherical aberration image of the first embodiment from left to right. Scattered and distorted graphs. As can be seen from Fig. 1, the image taking device of the first embodiment includes an imaging lens group (not labeled) and an electronic photosensitive element 170. The imaging lens group sequentially includes the aperture 100, the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the infrared filter filter 150, and the imaging surface 160 from the object side to the image side, and the electronic photosensitive The element 170 is disposed on the imaging surface 160 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (110-140) has a spacing on the optical axis.

The first lens 110 has a positive refractive power and is made of a plastic material. The object side surface 111 is convex at the near optical axis, and the image side surface 112 is concave at the near optical axis, and both are aspherical.

The second lens 120 has a negative refractive power and is made of a plastic material. The object side surface 121 has a concave surface at the near optical axis, and the image side surface 122 has a concave surface at the near optical axis, and both are aspherical.

The third lens 130 has a positive refractive power and is made of a plastic material. The object side surface 131 has a concave surface at the near optical axis, and the image side surface 132 has a convex surface at the near optical axis, and both are aspherical.

The fourth lens 140 has a negative refractive power and is made of a plastic material. The object side surface 141 is convex at the near optical axis, and the image side surface 142 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 142 has an inflection point.

The infrared filter filter 150 is made of glass and is disposed between the fourth lens 140 and the imaging surface 160 without affecting the focal length of the imaging lens group.

The aspherical curve equations of the above lenses are expressed as follows: Where: X: the point on the aspheric surface from the optical axis Y, the relative distance from the tangent plane on the aspherical optical axis; Y: the vertical distance between the point on the aspheric curve and the optical axis; R: curvature Radius; k: cone coefficient; and Ai: i-th order aspheric coefficient.

In the imaging lens group of the first embodiment, the focal length of the imaging lens group is f, the aperture value (f-number) of the imaging lens group is Fno, and the most in the imaging lens group Half of the large viewing angle is HFOV, and its values are as follows: f = 2.86 mm; Fno = 2.25; and HFOV = 37.7 degrees.

In the imaging lens group of the first embodiment, the refractive index of the second lens 120 is N2, which satisfies the following condition: N2 = 1.640.

In the imaging lens group of the first embodiment, the thickness of the second lens 120 on the optical axis is CT2, and the thickness of the third lens 130 on the optical axis is CT3, which satisfies the following condition: CT3/CT2 = 0.89.

In the imaging lens group of the first embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis is T12, and the distance between the second lens 120 and the third lens 130 on the optical axis is T23, which satisfies The following conditions: T23/T12=3.16.

Referring to Fig. 19, there are shown schematic diagrams of parameters Sag21 and Sag22 of the imaging lens group in the image taking device according to Fig. 1. As can be seen from FIG. 19, the horizontal displacement distance of the second lens object side surface 121 from the intersection on the optical axis to the maximum effective radius position of the second lens object side surface 121 on the optical axis is Sag21, and the second lens image side surface 122 is The horizontal displacement distance from the intersection point on the optical axis to the maximum effective radius position of the second lens image side surface 122 on the optical axis is Sag22, (the horizontal displacement distance is toward the object side direction, and SAG21 is defined as a negative value, if the image side direction, SAG21 It is then defined as a positive value, which satisfies the following conditions: |Sag22|/Sag21=-0.33.

In the imaging lens group of the first embodiment, the radius of curvature of the first lens object side surface 111 is R1, the radius of curvature of the first lens image side surface 112 is R2, and the radius of curvature of the second lens object side surface 121 is R3, The radius of curvature of the two lens image side surface 122 is R4, and the fourth lens object side surface 141 The radius of curvature is R7, and the radius of curvature of the fourth lens image side surface 142 is R8, which satisfies the following condition: (R1+R2)/(R1-R2)=-1.01; (R3+R4)/(R3-R4)= 0.01; and (R7+R8)/(R7-R8)=1.62.

In the imaging lens group of the first embodiment, the focal length of the second lens 120 is f2, and the focal length of the fourth lens 140 is f4, which satisfies the following condition: f4/f2 = 0.45.

In the imaging lens group of the first embodiment, the distance from the aperture 100 to the fourth lens image side surface 142 on the optical axis is SD, and the distance from the first lens object side surface 111 to the fourth lens image side surface 142 on the optical axis For TD, it satisfies the following conditions: SD/TD = 0.96.

In the imaging lens group of the first embodiment, the maximum angle of view in the imaging lens group is FOV, which satisfies the following condition: FOV = 75.4 degrees.

Refer to Table 1 and Table 2 below for reference.

Table 1 is the detailed structural data of the first embodiment of Fig. 1, in which the unit of curvature radius, thickness and focal length is mm, and the surfaces 0-12 sequentially represent the surface from the object side to the image side. Table 2 is the aspherical data in the first embodiment, wherein the cone surface coefficients in the a-spherical curve equation of k, and A1-A16 represent the aspherical coefficients of the first to the 16th order of each surface. In addition, the following table of the embodiments corresponds to the schematic diagram and the aberration diagram of the respective embodiments, and the definitions of the data in the table are the same as those of the first embodiment and the second embodiment, and are not described herein.

<Second embodiment>

Please refer to FIG. 3 and FIG. 4, wherein FIG. 3 is a diagram according to the present invention. A schematic diagram of an image taking device according to a second embodiment of the present invention, and FIG. 4 is a spherical aberration, astigmatism, and distortion curve of the second embodiment from left to right. As can be seen from Fig. 3, the image taking device of the second embodiment includes an imaging lens group (not labeled) and an electronic photosensitive element 270. The imaging lens group sequentially includes the aperture 200, the first lens 210, the second lens 220, the third lens 230, the fourth lens 240, the infrared filter filter 250, and the imaging surface 260 from the object side to the image side, and the electronic photosensitive The element 270 is disposed on the imaging surface 260 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (210-240) has a pitch on the optical axis.

The first lens 210 has a positive refractive power and is made of a plastic material. The object side surface 211 is convex at the near optical axis, and the image side surface 212 is convex at the near optical axis, and both are aspherical.

The second lens 220 has a negative refractive power and is made of a plastic material. The object side surface 221 is concave at the near optical axis, and the image side surface 222 is concave at the near optical axis, and both are aspherical.

The third lens 230 has a positive refractive power and is made of a plastic material. The object side surface 231 is concave at the near optical axis, and the image side surface 232 is convex at the near optical axis, and both are aspherical.

The fourth lens 240 has a negative refractive power and is made of a plastic material. The object side surface 241 is convex at the near optical axis, and the image side surface 242 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 242 has an inflection point.

The infrared filter filter 250 is made of glass and is disposed between the fourth lens 240 and the imaging surface 260 without affecting the focal length of the imaging lens group.

Refer to Table 3 and Table 4 below for reference.

In the second embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 3 and 4:

<Third embodiment>

Please refer to FIG. 5 and FIG. 6 , wherein FIG. 5 is a schematic diagram of an image capturing apparatus according to a third embodiment of the present invention, and FIG. 6 is a spherical aberration image of the third embodiment from left to right. Scattered and distorted graphs. As can be seen from Fig. 5, the image taking device of the third embodiment includes an imaging lens group (not labeled) and an electronic photosensitive element 370. The imaging lens group sequentially includes the aperture 300, the first lens 310, the second lens 320, the third lens 330, the fourth lens 340, the infrared filter filter 350, and the imaging surface 360 from the object side to the image side, and the electronic photosensitive The element 370 is disposed on the imaging surface 360 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (310-340) has a pitch on the optical axis.

The first lens 310 has a positive refractive power and is made of a plastic material. The object side surface 311 is convex at the near optical axis, and the image side surface 312 is convex at the near optical axis, and both are aspherical.

The second lens 320 has a negative refractive power and is made of a plastic material. The object side surface 321 is concave at the near optical axis, and the image side surface 322 is concave at the near optical axis, and both are aspherical.

The third lens 330 has a positive refractive power and is made of a plastic material. The object side surface 331 has a concave surface at the near optical axis, and the image side surface 332 has a convex surface at the near optical axis, and both are aspherical.

The fourth lens 340 has a negative refractive power and is made of a plastic material. The object side surface 341 is convex at the near optical axis, and the image side surface 342 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 342 has an inflection point.

The infrared filter filter 350 is made of glass and is disposed between the fourth lens 340 and the imaging surface 360 without affecting the focal length of the imaging lens group.

Refer to Table 5 and Table 6 below for reference.

In the third embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 5 and 6:

<Fourth embodiment>

Please refer to FIG. 7 and FIG. 8 , wherein FIG. 7 is a schematic diagram of an image capturing apparatus according to a fourth embodiment of the present invention, and FIG. 8 is a spherical aberration image of the fourth embodiment from left to right. Scattered and distorted graphs. As can be seen from Fig. 7, the image taking device of the fourth embodiment includes an imaging lens group (not labeled) and an electronic photosensitive element 470. The imaging lens group sequentially includes the aperture 400, the first lens 410, the second lens 420, the third lens 430, the fourth lens 440, the infrared filter 450, and the imaging surface 460 from the object side to the image side, and the electronic photosensitive The element 470 is disposed on the imaging surface 460 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (410-440) has a pitch on the optical axis.

The first lens 410 has a positive refractive power and is made of a plastic material. The object side surface 411 is convex at the near optical axis, and the image side surface 412 is concave at the near optical axis, and both are aspherical.

The second lens 420 has a negative refractive power and is made of a plastic material. The object side surface 421 is concave at the near optical axis, and the image side surface 422 is concave at the near optical axis, and both are aspherical.

The third lens 430 has a positive refractive power and is made of a plastic material. The object side surface 431 is concave at the near optical axis, and the image side surface 432 is convex at the near optical axis, and both are aspherical.

The fourth lens 440 has a negative refractive power and is made of a plastic material. The side surface 441 is convex at the near optical axis, and the image side surface 442 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 442 has an inflection point.

The infrared filter 450 is made of glass and is disposed between the fourth lens 440 and the imaging surface 460 without affecting the focal length of the imaging lens group.

Refer to Table 7 and Table 8 below for reference.

In the fourth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 7 and 8:

<Fifth Embodiment>

Please refer to FIG. 9 and FIG. 10 , wherein FIG. 9 is a schematic diagram of an image capturing apparatus according to a fifth embodiment of the present invention. FIG. 10 is a spherical aberration and image of the fifth embodiment from left to right. Scattered and distorted graphs. As is apparent from Fig. 9, the image pickup apparatus of the fifth embodiment includes an imaging lens group (not otherwise labeled) and an electron photosensitive element 570. The imaging lens group sequentially includes an aperture 500, a first lens 510, a second lens 520, and a third lens 530 from the object side to the image side. The fourth lens 540, the infrared filter 550 and the imaging surface 560, and the electronic photosensitive element 570 is disposed on the imaging surface 560 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (510~540) ) each has a spacing on the optical axis.

The first lens 510 has a positive refractive power and is made of glass. The object side surface 511 is convex at the near optical axis, and the image side surface 512 is convex at the near optical axis, and both are aspherical.

The second lens 520 has a negative refractive power and is made of a plastic material. The object side surface 521 is concave at the near optical axis, and the image side surface 522 is concave at the near optical axis, and both are aspherical.

The third lens 530 has a positive refractive power and is made of a plastic material. The object side surface 531 is concave at the near optical axis, and the image side surface 532 is convex at the near optical axis, and both are aspherical.

The fourth lens 540 has a negative refractive power and is made of a plastic material. The object side surface 541 is concave at the near optical axis, and the image side surface 542 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 542 has an inflection point.

The infrared filter 550 is made of glass and is disposed between the fourth lens 540 and the imaging surface 560 without affecting the focal length of the imaging lens group.

Refer to Table 9 and Table 10 below.

In the fifth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as in the first embodiment. I will not repeat them here.

The following data can be derived from Tables 9 and 10:

<Sixth embodiment>

Please refer to FIG. 11 and FIG. 12 , wherein FIG. 11 is a schematic diagram of an image capturing apparatus according to a sixth embodiment of the present invention, and FIG. 12 is a spherical aberration image of the sixth embodiment from left to right. Scattered and distorted graphs. As is apparent from Fig. 11, the image pickup apparatus of the sixth embodiment includes an imaging lens group (not otherwise labeled) and an electronic photosensitive element 670. The imaging lens group sequentially includes the aperture 600, the first lens 610, the second lens 620, the third lens 630, the fourth lens 640, the infrared filter 650, and the imaging surface 660 from the object side to the image side, and the electronic photosensitive The element 670 is disposed on the imaging surface 660 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (610-640) has a spacing on the optical axis.

The first lens 610 has a positive refractive power and is made of a plastic material. The object side surface 611 is convex at the near optical axis, and the image side surface 612 is convex at the near optical axis, and both are aspherical.

The second lens 620 has a negative refractive power and is made of a plastic material, and the object side surface 621 is concave at the near optical axis, and the image side surface 622 is at the near optical axis. Concave and both aspherical.

The third lens 630 has a positive refractive power and is made of a plastic material. The object side surface 631 is concave at the near optical axis, and the image side surface 632 is convex at the near optical axis, and both are aspherical.

The fourth lens 640 has a negative refractive power and is made of a plastic material. The object side surface 641 is convex at the near optical axis, and the image side surface 642 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 642 has an inflection point.

The infrared filter 650 is made of glass and is disposed between the fourth lens 640 and the imaging surface 660 without affecting the focal length of the imaging lens group.

Refer to Table 11 and Table 12 below for reference.

In the sixth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 11 and 12:

<Seventh embodiment>

Please refer to FIG. 13 and FIG. 14 , wherein FIG. 13 is a schematic diagram of an image capturing apparatus according to a seventh embodiment of the present invention, and FIG. 14 is a spherical aberration image of the seventh embodiment from left to right. Scattered and distorted graphs. As is apparent from Fig. 13, the image pickup apparatus of the seventh embodiment includes an imaging lens group (not otherwise labeled) and an electronic photosensitive element 770. The imaging lens group sequentially includes the aperture 700, the first lens 710, the second lens 720, the third lens 730, the fourth lens 740, the infrared filter 750, and the imaging surface 760 from the object side to the image side, and the electronic photosensitive The element 770 is disposed on the imaging surface 760 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (710-740) has a pitch on the optical axis.

The first lens 710 has a positive refractive power and is made of a plastic material. The object side surface 711 is convex at the near optical axis, and the image side surface 712 is convex at the near optical axis, and both are aspherical.

The second lens 720 has a negative refractive power and is made of a plastic material. The object side surface 721 is concave at the near optical axis, and the image side surface 722 is concave at the near optical axis, and both are aspherical.

The third lens 730 has a positive refractive power and is made of a plastic material. The object side surface 731 is concave at the near optical axis, and the image side surface 732 is convex at the near optical axis, and both are aspherical.

The fourth lens 740 has a negative refractive power and is made of a plastic material. The object side surface 741 is convex at the near optical axis, and the image side surface 742 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 742 has an inflection point.

The infrared filter 750 is made of glass, which is set in the fourth The lens 740 and the imaging surface 760 do not affect the focal length of the imaging lens group.

Refer to Table 13 and Table 14 below for reference.

In the seventh embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 13 and 14:

<Eighth Embodiment>

Referring to FIG. 15 and FIG. 16 , FIG. 15 is a schematic diagram of an image capturing apparatus according to an eighth embodiment of the present invention, and FIG. 16 is a spherical aberration image of the eighth embodiment from left to right. Scattered and distorted graphs. As is apparent from Fig. 15, the image pickup apparatus of the eighth embodiment includes an imaging lens group (not otherwise labeled) and an electronic photosensitive element 870. The imaging lens group sequentially includes an aperture 800, a first lens 810, a second lens 820, a third lens 830, a fourth lens 840, an infrared filter 850, and an imaging surface 860 from the object side to the image side, and the electronic photosensitive The element 870 is disposed on the imaging surface 860 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (810-840) has a pitch on the optical axis.

The first lens 810 has a positive refractive power and is made of a plastic material. The object side surface 811 is convex at the near optical axis, and the image side surface 812 is convex at the near optical axis, and both are aspherical.

The second lens 820 has a negative refractive power and is made of a plastic material. The object side surface 821 is concave at the near optical axis, and the image side surface 822 is concave at the near optical axis, and both are aspherical.

The third lens 830 has a positive refractive power and is made of a plastic material. The object side surface 831 has a concave surface at the near optical axis, and the image side surface 832 has a convex surface at the near optical axis, and both are aspherical.

The fourth lens 840 has a negative refractive power and is made of a plastic material. The object side surface 841 is convex at the near optical axis, and the image side surface 842 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 842 has an inflection point.

The infrared filter 850 is made of glass and is disposed between the fourth lens 840 and the imaging surface 860 without affecting the focal length of the imaging lens group.

Refer to Table 15 and Table 16 below for reference.

In the eighth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 15 and 16:

<Ninth embodiment>

Referring to FIG. 17 and FIG. 18, FIG. 17 is a schematic diagram showing an image capturing apparatus according to a ninth embodiment of the present invention. FIG. 18 is a spherical aberration and image of the ninth embodiment from left to right. Scattered and distorted graphs. As is apparent from Fig. 17, the image taking device of the ninth embodiment includes an imaging lens group (not labeled) and an electronic photosensitive element 970. The imaging lens group sequentially includes an aperture 900, a first lens 910, a second lens 920, a third lens 930, a fourth lens 940, an infrared filter filter 950, and an imaging surface 960 from the object side to the image side, and the electronic photosensitive The element 970 is disposed on the imaging surface 960 of the imaging lens group, wherein the refractive lens of the imaging lens group is four and each lens (910-940) has a pitch on the optical axis.

The first lens 910 has a positive refractive power and is made of a plastic material. The object side surface 911 is convex at the near optical axis, and the image side surface 912 is convex at the near optical axis, and both are aspherical.

The second lens 920 has a negative refractive power and is made of a plastic material. The object side surface 921 has a concave surface at the near optical axis, and the image side surface 922 has a concave surface at the near optical axis, and both are aspherical.

The third lens 930 has a positive refractive power and is made of a plastic material. The object side surface 931 has a concave surface at the near optical axis, and the image side surface 932 has a convex surface at the near optical axis, and both are aspherical.

The fourth lens 940 has a negative refractive power and is made of a plastic material. The object side surface 941 is convex at the near optical axis, and the image side surface 942 is concave at the near optical axis, and both are aspherical. In addition, the fourth lens image side surface 942 has an inflection point.

The infrared filter 950 is made of glass and is disposed between the fourth lens 940 and the imaging surface 960 without affecting the focal length of the imaging lens group.

Refer to Table 17 and Table 18 below for reference.

In the ninth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Tables 17 and 18:

<Tenth embodiment>

Referring to FIG. 20, a schematic diagram of a portable device 10 in accordance with a tenth embodiment of the present invention is shown. The portable device 10 of the tenth embodiment is a smart phone, and the portable device 10 includes an image capturing device 11 including an imaging lens group (not shown) and an electronic device according to the present invention. A photosensitive member (not shown) in which an electronic photosensitive member is disposed on an image forming surface of the imaging lens group.

<Eleventh Embodiment>

Referring to FIG. 21, a schematic diagram of a portable device 20 in accordance with an eleventh embodiment of the present invention is shown. The portable device 20 of the eleventh embodiment is a tablet computer, and the portable device 20 includes an image capturing device 21, and the image capturing device 21 includes an imaging lens group (not shown) and an electronic photosensitive element according to the present invention. Not disclosed), wherein the electronic photosensitive element is disposed on an imaging surface of the imaging lens group.

<Twelfth Embodiment>

Referring to FIG. 22, a schematic diagram of a portable device 30 in accordance with a twelfth embodiment of the present invention is shown. The portable device 30 of the twelfth embodiment is a head-mounted display (HMD), the portable device 30 includes an image capturing device 31, and the image capturing device 31 includes an imaging lens group according to the present invention ( The figure is not disclosed) and an electronic photosensitive element (not shown) in which the electronic photosensitive element is disposed on the imaging surface of the imaging lens group.

While the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and the invention may be modified and modified in various ways without departing from the spirit and scope of the invention. The scope is subject to the definition of the scope of the patent application.

100‧‧‧ aperture

110‧‧‧first lens

111‧‧‧Side side surface

112‧‧‧ image side surface

120‧‧‧second lens

121‧‧‧Side side surface

122‧‧‧ image side surface

130‧‧‧ third lens

131‧‧‧ object side surface

132‧‧‧Image side surface

140‧‧‧Fourth lens

141‧‧‧ object side surface

142‧‧‧ image side surface

150‧‧‧Infrared filter

160‧‧‧ imaging surface

170‧‧‧Electronic photosensitive element

Claims (23)

An imaging lens group comprising, in order from the object side to the image side, a first lens having a positive refractive power, the object side surface being convex at a near optical axis; and a second lens having a negative refractive power and an object side surface thereof The near optical axis is a concave surface, the image side surface is concave at the near optical axis, and the at least one surface thereof is aspherical; a third lens has a positive refractive power, and the object side surface is concave at the near optical axis, The side surface has a convex surface at a near optical axis, and has at least one surface aspherical surface; and a fourth lens having a negative refractive power, the image side surface having a concave surface at a near optical axis, and an object side surface and an image side thereof The surface is aspherical, wherein the fourth lens image side surface has at least one inflection point; wherein the imaging lens group has four refractive power lenses and two adjacent lenses are in the optical axis Each has a pitch, the thickness of the second lens on the optical axis is CT2, the thickness of the third lens on the optical axis is CT3, and the radius of curvature of the second lens object side surface is R3, the second lens image The radius of curvature of the side surface is R4, and the focal length of the second lens is f2 Focal length of the fourth lens element is f4, which satisfies the following conditions: 0.50 <CT3 / CT2 <1.12; -0.85 <(R3 + R4) / (R3-R4) <0.90; and 0 <f4 / f2 <0.90. The imaging lens assembly of claim 1, wherein the second lens, the third lens, and the fourth lens are both made of a plastic material, and both the object side surface and the image side surface are aspherical. The imaging lens group according to claim 2, further comprising: An aperture is disposed between a subject and the first lens, wherein a distance from the aperture to the side surface of the fourth lens image on the optical axis is SD, and the first lens object side surface to the fourth lens image side The distance of the surface on the optical axis is TD, which satisfies the following condition: 0.85 < SD / TD < 1.15. The imaging lens assembly of claim 3, wherein a distance between the first lens and the second lens on the optical axis is T12, and a distance between the second lens and the third lens on the optical axis is T23, It satisfies the following conditions: 1.0 < T23 / T12 < 5.0. The imaging lens group according to claim 3, wherein the maximum viewing angle in the imaging lens group is FOV, which satisfies the following condition: 70 degrees < FOV < 110 degrees. The imaging lens group according to claim 1, wherein the thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, which satisfies the following condition: 0.65<CT3/CT2<1.05 . The imaging lens group according to claim 6, wherein a radius of curvature of the first lens object side surface is R1, and a radius of curvature of the first lens image side surface is R2, which satisfies the following condition: -1.5<(R1+R2) ) / (R1-R2) < 0. The imaging lens group according to claim 1, wherein a radius of curvature of the fourth lens object side surface is R7, and a radius of curvature of the fourth lens image side surface is R8, which satisfies the following condition: 1.0 (R7+R8)/(R7-R8)<3.0. The imaging lens group according to claim 1, wherein the intersection of the second lens object side surface on the optical axis and the second lens object side surface is most effective The horizontal displacement distance of the radius position on the optical axis is Sag21. The horizontal displacement distance of the second lens image side surface on the optical axis to the maximum effective radius position of the second lens image side surface on the optical axis is Sag22, which satisfies The following conditions are: -1.0<|Sag22|/Sag21<0. The imaging lens group according to claim 1, wherein a focal length of the second lens is f2, and a focal length of the fourth lens is f4, which satisfies the following condition: 0.20 < f4 / f2 < 0.75. The imaging lens group according to claim 1, wherein a radius of curvature of the second lens object side surface is R3, and a radius of curvature of the second lens image side surface is R4, which satisfies the following condition: -0.60 < (R3 + R4) ) / (R3-R4) < 0.45. The imaging lens group according to claim 1, wherein the second lens has a refractive index of N2 which satisfies the following condition: 1.58 < N2 < 1.65. An image taking device comprising: the imaging lens group according to claim 1; and an electronic photosensitive element connected to the imaging lens group. A portable device comprising: the image capturing device as claimed in claim 13. An imaging lens group comprising, in order from the object side to the image side, a first lens having a positive refractive power, a convex surface of the object side surface near the optical axis, and a second lens having a negative refractive power and being made of a plastic material. The object side surface has a concave surface at a near optical axis, and at least one surface thereof is aspherical; a third lens has a positive refractive power and is made of a plastic material, and the object side surface is concave at a near optical axis, and the image side surface thereof is near The optical axis is convex and at least one of them The surface is aspherical; and a fourth lens has a negative refractive power and is made of a plastic material, and the image side surface is concave at the near optical axis, and the object side surface and the image side surface are aspherical surfaces, wherein the fourth surface is aspherical. The mirror side surface has at least one inflection point; wherein the imaging lens group has four refractive power lenses and two adjacent ones of the lenses have a pitch on the optical axis, and the imaging lens group further includes An aperture is disposed between a subject and the first lens, the thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, and the surface of the second lens is The radius of curvature is R3, the radius of curvature of the second lens image side surface is R4, the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the radius of curvature of the fourth lens object side surface is R7, The radius of curvature of the side surface of the fourth lens image is R8, which satisfies the following condition: 0.50<CT3/CT2<1.12; -1.50<(R3+R4)/(R3-R4)<0.90; 0<f4/f2<0.90; And 0 < (R7 + R8) / (R7-R8) < 3.5. The imaging lens assembly of claim 15, wherein a distance between the first lens and the second lens on the optical axis is T12, and a distance between the second lens and the third lens on the optical axis is T23, It satisfies the following conditions: 1.0 < T23 / T12 < 5.0. The imaging lens set according to claim 15, wherein the horizontal displacement distance of the second lens object side surface from the intersection on the optical axis to the maximum effective radius position of the second lens object side surface on the optical axis is Sag21, the first The horizontal displacement distance of the second lens image side surface on the optical axis to the maximum effective radius position of the second lens image side surface on the optical axis is Sag22, which satisfies the following condition: -1.0<|Sag22|/Sag21<0. The imaging lens group according to claim 15, wherein the focal length of the second lens is f2, and the focal length of the fourth lens is f4, which satisfies the following condition: 0.20 < f4 / f2 < 0.75. The imaging lens group according to claim 15, wherein a radius of curvature of the fourth lens object side surface is R7, and a radius of curvature of the fourth lens image side surface is R8, which satisfies the following condition: 1.0 (R7+R8)/(R7-R8)<3.0. The imaging lens set according to claim 15, wherein the thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, which satisfies the following condition: 0.65<CT3/CT2<1.05 . The imaging lens group according to claim 15, wherein a radius of curvature of the second lens object side surface is R3, and a radius of curvature of the second lens image side surface is R4, which satisfies the following condition: -1.10 (R3+R4)/(R3-R4)<0.90. An image taking device comprising: the imaging lens group according to claim 15; and an electronic photosensitive element coupled to the imaging lens group. A portable device comprising: the image capture device of claim 22.